SOME RHEOLOGICAL PROPERTIES OF WATER-SOLUBLE HYDROXYPROPYLCELLULOSE

Water‐soluble hydroxypropylcellulose having a hydroxypropyl molecular substitution (MS) of approximately 4.0 is a thermoplastic which may be fabricated in conventional plastic‐forming equipment. Its high‐temperature rheological properties have been measured over a wide range of temperatures, shear rates, frequencies, and diluent concentrations, by using the Weissenberg rheogoniometer. The rheological behavior of such hydroxypropylcelluloses is quite different from that of a nonpolar thermoplastic. This behavior may be interpreted in terms of two types of supermolecular structure: a crystalline phase which persists up to at least 215°C (as established by x‐ray examination), which is dispersed in an amorphous but highly hydrogen bonded matrix of stiff molecules. Copyright © 1969 John Wiley & Sons, Inc.